The present disclosure relates to the Passive optical network (PON) technology, and more particularly to a PON user terminal, and a method of power supply control and power supply state reporting for the user terminal.
PON technology is an optical access technology developed to support point-to-multipoint applications. Referring to FIG. 1, a PON typically comprises an optical line terminal (OLT) residing in the central office, a plurality of user terminal equipment residing in the user premises, which are typically optical network units (ONUs) or optical network terminals (ONTs), and an optical distribution network (ODN). The ODN comprises optical fiber and a passive optical network divider or coupler, and is located between the OLT and the user terminal equipment. The PON technology features all passive ODN components, a passive optical network divider and coupler serving only as an optical delivery and limiting means, no need for power supply and message processing, unlimited mean time between failures (MTBF), a flexible deployment of network due to its passive nature, and no need for room or power for equipment. The technology also features shared optical fiber, making possible significantly reduced optical fiber resources, which in turn leads to less expensive network access lines, a pure optical medium architecture, and a transparent optical fiber bandwidth network, putting the technology on the safe side for future service expansion.
In a PON, the optical fiber medium is used for data transmission, and the significantly improved bandwidth capacity over conventional technologies, such as copper cable and wireless Local Area Networks (LANs), allows for development of various services. The services that may be transmitted over a PON in the future include, for example, data access services, voice service, digital video service such as internet protocol television (IPTV), video on demand, conventional video services such as cable television and digital television, security data, and utility meter reading links to residential users. Incorporation of various service processing units (SPUs) into the PON user terminals may result in increased power consumption. Therefore, there is a need for saving the power consumed by such PON user terminals. Further, since some services require high reliability, the PON user terminal may be equipped with a backup battery so that it can rely on the backup battery for power supply if there is an outage in the alternating current (AC) main power supply, in which case saving the power consumed by the PON user terminal is particularly important.